1. Field of the Invention
The present invention relates to a liquid crystal injecting method for injecting liquid crystal into a liquid crystal cell.
2. Description of the Related Art
In general, a liquid crystal panel is constituted by two transparent substrates arranged to oppose to each other and bonded to each other with a sealing member interposed therebetween, on opposing surfaces of the transparent substrates transparent electrodes being formed, and liquid crystal injected in a space located between the transparent substrates and surrounded by the sealing material.
To manufacture such a liquid crystal panel, as shown in FIG. 6A, for example, first, an empty liquid crystal cell 4 is prepared by bonding two transparent substrates 1 and 2 with a sealing member 3 interposed therebetween, and not by injecting liquid crystal in a space located between the substrates 1 and 2 and surrounded by the sealing member 3. In this case, a liquid crystal injecting port 5 is formed in a center of a bottom portion of the sealing material 3 of the liquid crystal cell 4. The liquid crystal cell 4 is placed above a liquid crystal vessel 7 in a chamber 6. Then, the chamber 6 is evacuated by means of a vacuum pump (not shown) connected to the chamber 6 through a pipe 8. As a result, the inner space of the liquid crystal cell 4 is evacuated through the liquid crystal injecting port 5. Thereafter, as shown in FIG. 6B, the bottom portion of the liquid crystal cell 4 is dipped into liquid crystal 9 contained in the liquid crystal vessel 7. In this state, atmosphere is introduced into the vacuum chamber 6 through the pipe 8, resulting in that the liquid crystal 9 is injected into the inner space of the liquid crystal cell 4 through the liquid crystal injecting port 5. Then, the liquid crystal cell 4 is taken out from the chamber 6, and the liquid crystal injecting port 5 is sealed with sealing material (not shown).
In the conventional liquid crystal injecting method as described above, since all the bottom portion of the liquid crystal cell 4, in which the liquid crystal injecting port 5 is formed, is dipped into the liquid crystal 9 in the liquid crystal vessel 7, the area of that portion of the liquid crystal cell 4 which is dipped in the liquid crystal 9 is considerably large relative to the size of the liquid crystal injecting port 5. Therefore, a large amount of foreign substances adhere on an outer surface of the liquid crystal cell 4 or impurities such as alkaline components of the transparent substrates 1 and 2 (if the transparent substrates are made of glass) are mixed in the liquid crystal 9, resulting in contamination and degradation of the liquid crystal 9. If the contaminated liquid crystal 9 is injected into the liquid crystal cell 4, the quality of display may be lowered. In addition, the liquid crystal 9 unnecessarily adhered to the outer surface of the bottom portion of the liquid crystal cell 4 must be cleaned with a solvent in a subsequent step. Thus, expensive liquid crystal is wasted in a large amount, which increases the cost of manufacturing liquid crystal panels.